Recessed-gate quasi-enhancement-mode AlGaN/GaN high electron mobility transistors with oxygen plasma treatment
He Yun-Long1, Wang Chong1, †, , Mi Min-Han1, Zheng Xue-Feng1, Zhang Meng2, Zhao Meng-Di1, Zhang Heng-Shuang1, Chen Li-Xiang2, Zhang Jin-Cheng1, Ma Xiao-Hua1, 2, Hao Yue1, 2
       

(a) Cross-sectional schematic of sample A, (b) cross-sectional schematic of sample B. (c) Cross-sectional schematic of sample C, (d) electron-microscope image of enhancement-mode HEMT.